Page 53 - Nutrient Management Planning Guide

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Chapter 2.2

Positively charged ions (cations) are •

attracted and loosely held (adsorbed) to the negative charge of soil particles. Adsorbed cations can be exchanged for •

others in a process called cation exchange. The amount of exchangeable cations per unit weight of soil is referred to as the CEC. Cation exchange is a critical process for •

supplying nutrients to developing crops. Organic matter is an important source •

of nutrients. Soil organic matter content influences CEC and can be influenced by environmental conditions and management practices.

Soil pH affects the availability of several •

nutrients essential for crop growth and development and also influences the activity of soil organisms. Salinity can limit crop growth by interfering •

with plant water uptake. This reduces yield potential and should factor into nutrient management.

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